/* ==========================================================================
   1. LATEX / ACADEMIC TYPOGRAPHY & LAYOUT
   ========================================================================== */
@import url('https://fonts.googleapis.com/css2?family=Latin+Modern+Roman&family=Lora:ital,wght@0,400;0,600;1,400&family=Source+Code+Pro&display=swap');

body {
  background-color: #f4f4f6;
  color: #111111;
  font-family: 'Lora', 'Latin Modern Roman', Georgia, serif;
  line-height: 1.7;
  margin: 0;
  padding: 40px 20px;
  display: flex;
  justify-content: center;
}

/* Document Container */
.secure-notes {
  background: #ffffff;
  max-width: 800px;
  width: 100%;
  padding: 60px 80px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
  border: 1px solid #e1e1e1;
  position: relative;
  box-sizing: border-box;
  
  /* SECURITY: Prevent text selection */
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

/* Header Styling */
.doc-header {
  text-align: center;
  margin-bottom: 40px;
}

.doc-meta {
  font-size: 0.85rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: #666;
  margin-bottom: 5px;
}

.doc-title {
  font-size: 2.2rem;
  font-weight: 600;
  margin: 10px 0;
}

.doc-divider {
  height: 2px;
  background-color: #111;
  width: 100%;
  margin-top: 20px;
}

/* Notes Content & Sections */
.note-section {
  margin-bottom: 35px;
}

h2 {
  font-size: 1.4rem;
  border-bottom: 1px solid #ddd;
  padding-bottom: 5px;
  margin-top: 30px;
  color: #000;
}

h3 {
  font-size: 1.15rem;
  margin-top: 20px;
}

p, li {
  font-size: 1.05rem;
  color: #222;
}

.formula-box {
  background-color: #fdfdfd;
  border: 1px solid #e5e5e5;
  border-radius: 4px;
  padding: 10px;
  margin: 15px 0;
  text-align: center;
  overflow-x: auto;
}

/* ==========================================================================
   2. LATEX-STYLE INTERNAL CROSS-REFERENCE LINKS (\hyperref)
   ========================================================================== */
a.latex-internal-link {
  color: #004b87; /* Classic LaTeX hyperref blue */
  text-decoration: none;
  border-bottom: 1px dotted #004b87;
  padding: 0 2px;
  transition: background-color 0.15s ease, color 0.15s ease;
  cursor: pointer;
}

a.latex-internal-link:hover {
  background-color: rgba(0, 75, 135, 0.1);
  border-bottom: 1px solid #004b87;
}

/* Target highlight flash effect upon navigating */
.note-section:target {
  animation: highlightTarget 1.5s ease-out;
}

@keyframes highlightTarget {
  0% { background-color: rgba(255, 235, 59, 0.4); }
  100% { background-color: transparent; }
}

/* ==========================================================================
   3. SECURITY & ANTI-SCREENSHOT / PRINTING MEASURES
   ========================================================================== */

/* Dynamic Watermark Overlay */
/* Dynamic Watermark Overlay */
.watermark-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.13;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around;
  align-content: space-around;
  overflow: hidden;
}

.watermark-text {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  transform: rotate(-30deg);
  font-weight: 700;
  color: #000;
  white-space: nowrap;
  margin: 35px 25px;
  line-height: 1.35;
  font-size: 0.95rem;
}

.watermark-text span {
  display: block;
}

.watermark-text .wm-name {
  font-size: 1.05rem;
  font-weight: 800;
}

.watermark-text .wm-email {
  font-size: 1rem;
  font-weight: 600;
}

.watermark-text .wm-phone {
  font-size: 1rem;
  font-weight: 600;
  color: #333;
}

/* Window Blur Blur Protection (Anti-Screenshot/Snipping Tool) */
body.blurred-content .secure-notes {
  filter: blur(20px);
  pointer-events: none;
}

/* Anti-Print Rule */
@media print {
  body {
    display: none !important;
  }
}

html {
  scroll-behavior: smooth;
}

body {
  animation: fadeIn 0.4s ease-in-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}